Researchers identified a gene that puts women at a higher risk of developing Alzheimer's.

A research team found that carrying the gene variant ApoE4 puts women at a higher risk of developing Alzheimer's than it does for men, a Stanford University Medical Center news release reported.

Researchers studied a large pool of data encompassing over 8,000 people (mostly over the age of 60) to see which individuals had progressed from good cognitive health to mild impairment or Alzheimer's.

The finding could help researchers gain insight into the underlying cause of Alzheimer's. About one in eight people over the age of 65 in the United States suffers from Alzheimer's and is more prevalent in women.

"Even after correcting for age, women appear to be at greater risk," Michael Greicius, MD, assistant professor of neurology and neurological sciences and medical director of the Stanford Center for Memory Disorders said in the news release.

In one group of data the team looked at "clinical assessments of 5,000 people whose test results were normal at the outset and 2,200 people who had initially showed signs of mild cognitive impairment," the news release reported. They found ApoE4 carriers had an increased the risk of developing mild cognitive impairment (which usually leads to Alzheimer's), but this risk was only "marginal" for men and was prevalent for women.

"Our study showed that, among healthy older controls, having one copy of the ApoE4 variant confers a substantial Alzheimer's disease risk in women, but not in men," Greicius said.

The second repository contained "imaging data and measurements of several biochemical substances from spinal fluid that can serve as useful biomarkers of impending mild cognitive impairment and eventual Alzheimer's disease," the news release reported. The analysis included 1,000 patients; this study also found a disparity between men and women.

The ApoE gene is responsible for moving fatty substances throughout the body; brain function depends on this process along the cell membranes. About in in four people carry the ApoE4 gene.

"Why the difference? Now we can work toward understanding the cause of this sex difference, which may reveal new potential drug targets," lead author Andre Altmann, PhD, said in the news release.